This policy setting controls whether Outlook 2007 users can expand distribution lists when addressing e-mail messages.
If you enable this policy setting, Outlook 2007 users cannot expand distribution lists.
If you disable or do not configure this policy setting, when Outlook 2007 users add a distribution list to the To, CC, or BCC fields of an e-mail message or other item, they can expand the distribution list to see the e-mail addresses of everyone in the list.
| Registry Hive | HKEY_CURRENT_USER |
| Registry Path | Software\Policies\Microsoft\Office\12.0\Outlook\Options\Mail |
| Value Name | DisableDLExpansion |
| Value Type | REG_DWORD |
| Enabled Value | 1 |
| Disabled Value | 0 |